Home/ News & Events
[Research News] Responses of species and phylogenetic diversity of fish communities in the Lancang River to hydropower development and exotic invasions
Date:04/02/2018

   A recent study conducted by Prof. Chengzhi Ding's team focused on the variation of fish diversity in the Lancang River in the context of hydropower development and widespread exotic invasions. The research article named "€œResponses of species and phylogenetic diversity of fish communities in the Lancang River (LCR) to hydropower development and exotic invasions" by Prof. Chengzhi Ding (corresponding author), Liqiang Chen and their students Chao Zhang (first author), Liuyong Ding and Jie Sun has been published in an Elsevier'€™s Journal-Ecological Indicators (online:https://www.sciencedirect.com/science/article/pii/S1470160X18301481).

   In this study, they subdivided the mainstream of the Lancang River into 12 regions to examine the changes in the species-level and phylogenetic diversity of fish assemblages during the past three decades. They found that disturbances by dams and widespread introductions of exotic fishes have induced a marked loss of native species (average 36.8 species disappeared per region, accounting for 47.2% of the historical native species) in the downstream regions over time, whereas few native species were disappeared (average 4 species disappeared, accounting for 23.8% of the historical native species) in the upstream regions. In terms of phylogenetic diversity, however, the average taxonomic distinctness (Δ+, a taxonomic proxy for phylogenetic diversity) of the entire assemblages significantly increased (an increase of 4.4% compared to historical Δ+) in all regions, while native Δ+ insignificantly decreased in downstream regions, and the variation in taxonomic distinctness (Δ+, a proxy for variation in phylogenetic diversity) of the entire assemblages significantly increased (24.6%) in downstream regions, while native Δ+ significantly decreased (12.0%) in all regions. Such changes in phylogenetic diversity were triggered by invasions by distantly related exotic species and disappearances of congeneric endemic species. Across the LCR, the relationships between species richness, Δ+, and Δ+ and altitude all became obscure due to the combined effect of introductions and disappearances.

   Their study showed that intensive hydropower development and exotic invasions have significantly affected both the taxonomic and phylogenetic diversity of fish assemblages in the LCR, especially in its downstream region. However, the response of phylogenetic diversity to human disturbance was inconsistent with that of species diversity, implying that examining the response of phylogenetic diversity could provide additional information for assessing the impacts of human domination. The study also found that the disappearance rate and rate of change in the taxonomic distinctness of native assemblages showed negative correlations with the distances of cascade dams in dammed regions, providing reference to further research on cascade hydropower development.

  This work was supported by the National Key Research and Development Program of China (2016YFA0601601), the National Natural Science Foundation of China (grants 41501574, 31770460) and the Yunnan Applied Basic Research Projects (2016FB079), the project Balancing River Health and Hydropower Requirements in the LCR Basin, which is a part of the CGIAR Research Program on Water, Land and Ecosystem (WLE) and supported by CGIAR Fund Donors.

Fig.1 Study area and Linear regression relationships between (A) species richness, (B) average taxonomic distinctness (Δ+) and (C) variation in taxonomic distinctness (Λ+) and average altitude in the historical and current periods.


 

Fig. 2 Rate of change in species richness, average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) for native assemblages versus reach length in dammed regions.

News & Events
Quick links
© 2016 Yunnan University. All Rights Reserved ICP:滇ICP备05004791
0871-61234567 Email Address
Technical support:www.aykj.net